2-Explorer

Question

Issues with different accuracies

Forum|Forum|9 years ago
January 24, 2017
4 replies
5445 views

Hello

Can I have different accuracy within an assembly? What can be the issues of same?

Let me elaborate this.

Suppose I have an assembly (MAIN.ASM) having 4 parts (A,B,C and D.prt) and one sub assembly (SUBASSEMBLY.asm).Sub assembly has two parts (E and F.prt).

All parts, sub assembly are having relative accuracy of 0.0012 and all has been assembled into main assembly having relative accuracy of 0.0012.

Now in a scenario, I need to add a feature into E.prt which is asking for absolute accuracy of 0.0001. I am changing accuracy and updating part.

With these update, will there be any effect on MAIN.ASM like regeneration failure or constraint failure or any other failure?

What would be effect on interference or clearance with this update?

Hope I have clarified my doubt. Feel free to ask in case of any confusion.

Regards

Ketan

Assembly Design

D

dcaucutt

1-Visitor

I assemble parts with different accuracies all the time and have no major issues.

M

mbonka

2-Explorer

Hello

please see following link: Your model accuracy? Other users described some problems around model accuracy.

What would be effect on interference or clearance with this update?

- Not able to answer your question .

The only problem l have had is TOP-DOWN design.

- if l share/propagate geometry from main skeleton to subskeletons or parts, than it can fail due different model accuracy.

If possible, keep one model accuracy in whole project.

More expirienced users give you better tips...

Regards

Milan Bonka

T

TomD.inPDX

17-Peridot

You have to be careful about setting up something like this. It requires planning. Typically, you also have the discipline to minimize your dependencies to required interfaces only and a type of skeleton (core Creo) that the assembly extension provides.

The biggest problem I see with this is when you decide to start using cross-component-constrained parts in a new project.

The way I look at it, if you go this route, treat your assembly as a single inseparable part. Otherwise, be prepared for reference searches that seem to have nothing to do with your current effort.

K

Ketan_Lalcheta

Author

2-Explorer

I am not able to understand why I need to use assembly as inseparable part? It's already having accuracy of 0.0012 which all other models are having... I have changed accuracy of part e... If part e is acceptable by main assembly, then why it's not acceptable by other models?

Did you mean this restriction or something else by saying inseparable part?

M

manjunathrv

17-Peridot

In my experience, there will not be any issues in the assembly unless there is an intersecting feature like an assembly cut or any merge features....that intersects with the part having different accuracy.

D

dcaucutt

1-Visitor

Agreed, Manjunath RV.

KenFarley

21-Topaz II

A horrible problem we had with assemblies is if the accuracy of some of the constituents is at the default (0.0012 relative in inch units), a global interference check showed everything being okay, when there was, in the "real world" an interference between two parts. I don't recall the combination of accuracy settings in the parts and assemblies, but luckily it showed up when the machinist was programming the parts and noticed something was not adding up. Just another consideration.